xen: add missing includes

* xen/console.h: Add missing includes.
kern/sched_prim.h: remove unnecessary __GNUC__ #ifdef

Attribute noreturn is used irrespective of __GNUC__. Remove
unnecessary #ifdef.

* kern/sched_prim.h [__GNUC__]: Remove #ifdef.
Cleanup of the copyin() and copyout() calls

* device/ds_routines.c (device_write_trap) (copyin) (data): Cast to (void *). Argument is an address.
(device_write_trap) (copyin) (io_data): Don't cast.
(device_writev_trap) (copyin) (iovec, stack_iovec): Likewise.
(device_writev_trap) (copyin) (data, p): Cast to (void *). Arguments are addresses.
* kern/bootstrap.c (build_args_and_stack) (copyout) (arg_count, string_pos, zero): Don't cast.
* kern/ipc_mig.c (syscall_vm_map) (copyin, copyout) (addr, address): Likewise.
(syscall_vm_allocate) (copyin, copyout) (addr, address): Likewise.
(syscall_task_create) (copyout) (name, child_task): Likewise.
(syscall_mach_port_allocate) (copyout) (name, namep): Likewise.
* kern/time_stamp.c (copyout) (temp, tsp): Likewise.
device: qualify pointers whose dereferenced values are constant with const
i386: qualify pointers whose dereferenced values are constant with const
ipc: qualify pointers whose dereferenced values are constant with const
kern: qualify pointers whose dereferenced values are constant with const
util: qualify pointers whose dereferenced values are constant with const
vm: qualify pointers whose dereferenced values are constant with const
Mark functions that don't return with attribute noreturn
kern: avoid the casts in enqueue_head() and enqueue_tail()

* kern/eventcount.c (simpler_thread_setrun) (enqueue_head) (th): Avoid the cast.
* kern/thread.c (thread_halt_self) (enqueue_tail) (thread): Likewise.
* kern/thread_swap.c (thread_swapin) (enqueue_tail) (thread): Likewise.
i386: add missing includes

* i386/i386at/kd_event.h: Add missing includes.
Declare void argument lists (part 2)

Declare void argument lists that were not declared in the first
part of this patch and

* kern/sched_prim.h (recompute_priorities): Fix prototype.
* kern/startup.c (setup_main) (recompute_priorities): Fix call.
ddb/db_watch.c (db_watchpoint_cmd): remove forward declaration

* ddb/db_watch.c (db_watchpoint_cmd) (db_option): Remove forward declaration.
kern/strings.c (strlen): mark with attribute pure

* kern/strings.c (strlen): Mark with attribute pure.
Mark pure functions with attribute pure
Merge branch 'master' of git.savannah.gnu.org:/srv/git/hurd/gnumach